I didn't spend any significant time outside the suburbs until I was a young teenager. When I was exposed to real fields for the first time (unlike, say, the fields in a battlefield park) I wasn't quite sure what to make of them.
When you grow up in quasi-urban areas, a fence pretty much serves one purpose: to divide this from that. Fences represent boundaries of possession and ownership, of rightfulness and trespass. You are on your side; they are on their side, and never the twain shall mingle, much less meet.
But fences also serve the function of constraining things, and as a suburban kid it took me a long time to realize that out in the country, fences and boundaries were not synonymous. There were boundaries that were not marked by fences; there were fences that did not represent boundaries, only constraints. And sure enough, there were fences that also happened to be boundaries.
I can still remember the first frisson of delight in crossing a fence into a boundless field, realizing at that instant I was not the thing to be constrained. The world became a much larger, grander place in that moment.